How should I have done it ?

[OldWood]

The three photos show the story.

Having done the repair to the base, I then mounted the bowl on a button chuck in order to tidied up the underside of the plug. I was concerned about what tool to use so opted for a scraper - OK to begin with !!

How should I have done it and what tool?

Rob
[attachment=2]Maple_Bowl_1.jpg[/attachment]
[attachment=1]Maple_Bowl_2.jpg[/attachment]
[attachment=0]Maple_Bowl_4.jpg[/attachment]

 

[T. Walton]

A scraper is the wrong tool to use when holding in a button chuck, a scraper tends to pull at the work as it cuts and will try to pull it out of the button chuck, my suggestion would be to use either a 1/4 bowl gouge or a 3/8 spindle gouge with these the bevel is rubbing and pushing the work towards the button chuck while taking a slicing cut. Take small light cuts and gently remove the waste wood.
Tony

 

[OldWood]

Thanks Tony - I needed the mechanics to understand what went wrong. It's all a learning process but it would be nice to have some output once in a while!

Rob

 

[Blister]

Rob

From what I can see you are up against 5 problems

1, a very thin base
2, clamping pressure when held in button jaws
3, Speed when turning using the button jaws
4, did you have the tail stock in use
5, Chisel choice

What could you have done

1, Nothing regarding the thin base
2, Minimum clamping pressure just enough to hold it
3, speed , again minimum to be able to get a cut 500 rpm to 1000 absolute max if you are brave
4 Tail stock , Slide the tail stock up to the base with a revolving center just touching to offer support and stop the bowl moving out of the button jaws
5, Chisel choice , mine would be a 3/8 fingernail grind bowl gouge used on edge in a shear scraping mode using VERY light cuts , when finished remove bowl and trim off the nib left in the center

Hope this helps :wink:

 

[OldWood]

Rob

From what I can see you are up against 5 problems

1, a very thin base
2, clamping pressure when held in button jaws
3, Speed when turning using the button jaws
4, did you have the tail stock in use
5, Chisel choice

What could you have done

1, Nothing regarding the thin base
2, Minimum clamping pressure just enough to hold it
3, speed , again minimum to be able to get a cut 500 rpm to 1000 absolute max if you are brave
4 Tail stock , Slide the tail stock up to the base with a revolving center just touching to offer support and stop the bowl moving out of the button jaws
5, Chisel choice , mine would be a 3/8 fingernail grind bowl gouge used on edge in a shear scraping mode using VERY light cuts , when finished remove bowl and trim off the nib left in the center

Hope this helps :wink:

Well it had a very thin base, part of it none(!) but that was about 10mm by the time it had that very pretty bit of laburnum added, but that is just being picky.

The rest of it, Blister, you're right.
Possibly a bit high on the clamping force; speed may have been around 1000; I forgot I should have used the back centre, which in many ways was the biggest omission; and I've already been chastised for the incorrect tool choice

Many thanks for your input, Blister - in theory it shouldn't happen again as I just WILL NOT be going through the base again.

But I did like the laburnum base in-fill and will repeat that.

Rob

 

[SVB]

A not of caution on the advice above - many button jaw sets have a maximum rpm of around 800 so you need to consider this also.

S